CN106232002A - The EPT method that the electrical conductivity of the stability and speed with enhancing is rebuild - Google Patents
The EPT method that the electrical conductivity of the stability and speed with enhancing is rebuild Download PDFInfo
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Abstract
A kind of electrical property tomography method, for rebuilding the spatial distribution of electrical conductivity (σ) according to the magnetic resonance image data of at least part of magnetic resonance image (MRI) representing objects (20), described spatial distribution covers at least part of of the district of described magnetic resonance image (MRI), and said method comprising the steps of: split described magnetic resonance image (MRI)；Acquisition phase value is extrapolated；Acquisition phase value is replaced by described extrapolation phase value；Transform in frequency domain；Respectively the numerical second derivative through frequency domain transform is multiplied by acquisition phase value and the described numerical second derivative through frequency domain transform is multiplied by extrapolation phase value；And the result being multiplied is transformed in spatial domain.Also include MRI system and the software module of correspondence.
Description
Technical field
The present invention relates to a kind of for the magnetic resonance figure according at least part of magnetic resonance image (MRI) representing objects
Electrical property tomography (EPT) method as the spatial distribution of data reconstruction electrical conductivity.
Background technology
Article " Determination of Electric Conductivity and at Katscher, U. et al.
Local SAR Via B1Mapping”(IEEE Trans.Med.Imag.2009；In 28:1365-1374), it has been suggested that
Led from the spatial sensitivity profile of the radio-frequency coil of the application of magnetic resonance imaging system by electrical property tomography (EPT) method
Go out the electrical conductivity of the part of objects.It is right that the electrical property of the part of objects can be used as potentially for supporting
Object carries out the extraneous information diagnosing to distinguish health tissues with malignant tissue's (such as tumor).
Article " the Quantitative Conductivity and Permittivity Imaging of Voigt, T. et al.
of the Human Brain Using Electric Properties Tomography”(Magn.Reson.in
Med.2011；66:456-466) describe the phase of a kind of radio-frequency transmissions field for basis employed in nuclear magnetic resonance
Bit image rebuilds method and the formula of the space distribution of conductivity of the part of objects.
The Proc ISMRM 2012 of Katscher et al. page 3482 describe a kind of based on fitting within Tx phase place
The EPT algorithm for reconstructing of partial paraboloid line function.The publication describes fitting of parabola and can be used removal boundary artifacts.
Expect to provide the spatial distribution of the electrical conductivity of the part for rebuilding objects according to magnetic resonance image data
Quickly and the method for robust.
Summary of the invention
Conductivityσ can be via following formula according to transmitting-receiving phase place(transmitting-receiving phase place is rebuild quantitatively via formula (1)It is to penetrate
Frequently launching phase and radio frequency accept the superposition in stage),
Wherein, μ0Referring to permeability of vacuum, ω refers to Larmor frequency, and Δ=2Refer to so-called laplacian or
Laplace operator.
In numerical method, the transmitting-receiving phase place of gathered magnetic resonance image (MRI) is passed through in the calculating of Laplace operatorWith micro-
The convolution of pyrene realizes.
The CPU process time needed for conductivityσ that calculates can be by by differential core and transmitting-receiving phase placeFourier transform arrives
Being significantly reduced in frequency domain, convolution is reduced to only multiplying by this.But, in a frequency domain, between different anatomic compartment
, the especially border between tissue and air can not be identified, thus causes as the La Pula performing to cross over organizational boundary
Serious artifact during this computing.
Such as, the phase evolution between soft tissue and lipid is for such as balancing the magnetic that Turbo Field Echo (bFFE) is selected
Resonance image-forming technology can be discontinuous.Additionally, skeleton, ligament and other kinds can illustrate that the magnetic resonance close to zero is believed
Number, and therefore there is the most noisy magnetic resonance image (MRI) signal phase.
Therefore, it is an object of the invention to provide a kind of spatial distribution for rebuilding electrical conductivity according to magnetic resonance image data
Based on electrical property tomography (EPT) quickly and the method for robust, it generates the artifact of truth of a matter amount as far as possible.
In one aspect of the invention, described purpose is realized by a kind of electrical property tomography method, described side
Method for rebuilding the sky of electrical conductivity according to the magnetic resonance image data of at least part of magnetic resonance image (MRI) representing objects
Between be distributed.Described spatial distribution covers at least part of of the district of magnetic resonance image (MRI).
Said method comprising the steps of:
-it is the body outside the voxel corresponding to volume of interest and described volume of interest by described Magnetic Resonance Image Segmentation
Element, wherein, is separated outside the described voxel corresponding to described volume of interest and described volume of interest by partitioning boundary
Described voxel；
-the most described magnetic resonance image (MRI) of the voxel corresponding to described volume of interest of described partitioning boundary will be adjacent to
The acquisition phase value of data is extrapolated, to obtain the body for the outside and neighbouring described volume of interest of described volume of interest
The extrapolation phase value of long-pending voxel；
-replaced the body corresponding to the outside and neighbouring described volume of interest of described volume of interest by described extrapolation phase value
The acquisition phase value of the MR data of long-pending voxel；
-transforming in frequency domain: numerical value kernel representation numerical second derivative, described acquisition phase value corresponds to described body interested
Long-pending described voxel, and described extrapolation phase value is corresponding to the outside and neighbouring described volume of interest of described volume of interest
Described voxel；
-respectively the numerical second derivative through frequency domain transform is multiplied by described acquisition phase value and by through frequency domain transform
Numerical second derivative is multiplied by extrapolation phase value；And
-result of the step being multiplied is transformed in spatial domain.
By this way, if representing that the numerical value core of numerical second derivative is applied to the body of dramatically different electrical conductivity
Element, then the boundary artifacts that may generate can be lowered or be avoided by.
Therefore, described method magnetic resonance image data the most wherein represents and includes the head of objects, liver, kidney
Be particularly effective in the case of the magnetic resonance image (MRI) of in prostate.
In one embodiment, the volume of the outside and neighbouring volume of interest of volume of interest can be included in two linearly
At least five voxel on unrelated direction, it is highly preferred that at least ten voxel, and most preferably, two linear independence sides
Ten voxels of at least two upwards.
Preferably, extrapolation phase value is selected as constant.Thus, the voxel of the volume of interest of partitioning boundary it is adjacent to
Big step in the phase place of the voxel of volume of interest outside and neighbouring with volume of interest can be easily avoided by.
In the preferred embodiment of method, the step of extrapolation includes the three dimensional parabolic line extrapolation of phase value.By this way,
Extrapolation phase value can easily be calculated.
In another preferred embodiment of method, the step of segmentation uses dividing method based on model to perform.Thus,
The mould shapes of the part of objects can be adjusted to match to parametrization the anatomical detail of the part of objects
Thus split the most accurately for obtaining, and it is obtained in that the more accurate spatial distribution of electrical conductivity.The surface of model is permissible
There to be little surface model (faceted mode) to represent, its be plotted as approximate anatomical detail surface such as rectangle or triangle
A series of plane domains.Generally, in surface represents, surface can be suitable to show as to those skilled in the art
Any other pattern represent, such as wire frame representation.
In a further preferred embodiment, method includes the step of filtering in the spatial domain, and wherein, described step is by phase
The result of the step taken advantage of performs, for realizing noise reduction after transforming to the step in spatial domain.
In a still further aspect thereof, it is provided that a kind of at least part of magnetic being arranged to gather objects
The magnetic resonance imaging system of resonance image, including:
-check space, its be provided as by described objects at least described in be partially located in described inspection space
In；
-main magnet, it is arranged in described inspection space generate static magnetic field B0；
-magnetic gradient coil system, it is arranged to generation and is added to described static magnetic field B0Gradient magnetic；
-at least one radio-frequency antenna equipment, it is arranged to radio-frequency (RF) excited field B1It is applied to described objects
The atomic nucleus of described part or described part in atomic nucleus for magnetic resonance excitation,
-at least one radio-frequency antenna equipment, it is arranged to from by applying described radio-frequency (RF) excited field B1Excitation
The described atomic nucleus of described part of described objects or described part in described atomic nucleus receive magnetic resonance signal；
-control unit, its function being arranged to control described magnetic resonance imaging system；And
-processor unit, its step being configured to perform any or a combination thereof in method as disclosed herein.
Preferably, the control unit of magnetic resonance imaging system is configured to starting impulse sequence, wherein, each pulse train
It is configured to generate radio-frequency field via at least one radio-frequency antenna equipment, and generates magnetic gradient via magnetic gradient coil system
?.Pulse train is to static magnetic field B0Change insensitive.
In one embodiment, control unit can be configured to starting impulse sequence, described pulse train be suitable for
At least one in Xia:
-equilibrium gradient steady state free precession (bSSFP) sequence, especially three-dimensional balancing Turbo Field Echo (3D-bFFE) sequence
Row, and
-three-dimensional spin-echo sequence, especially 3-dimensional fast spin echo (3D-TSE) sequence.
In still yet another aspect of the present, it is provided that a kind of software module, for performing according to representing objects
In the mean disclosed above of the spatial distribution that the magnetic resonance image data of at least part of magnetic resonance image (MRI) rebuilds electrical conductivity
Any one or the embodiment of a combination thereof.Method step to be implemented is converted into the program code of described software module, its
In, described program code may be implemented in the memory cell of described magnetic resonance imaging system and can be by described nuclear magnetic resonance
The processor unit of system performs.Described processor unit can be the described processor unit of described control unit, described control
Unit processed is generally used for controlling the function of magnetic resonance imaging system.Alternatively or addedly, described processor unit can be
Another processor unit, it is specifically designed at least some in operation method step.
Described software module is capable of the robust to described method and runs reliably and can allow for method step
Quick amendment.
Accompanying drawing explanation
These and other aspects of the present invention will be according to embodiment as described below it is clear that and will be with reference to hereafter
The embodiment described is elaborated.But, such embodiment does not necessarily means that the four corner of the present invention, and therefore to right
Claim and make with reference to explain the scope of the present invention herein.
In the accompanying drawings:
Fig. 1 shows the indicative icon of the part of the embodiment of the magnetic resonance imaging system according to the present invention,
Fig. 2 is the flow chart of the embodiment of the method according to the invention, and
Fig. 3 (a) illustrates to 3 (h) and the embodiment of the method according to the invention is applied the head to objects
The example of magnetic resonance image (MRI).
Reference numerals list
10 magnetic resonance imaging system B0 static magnetic fields
12 scanning element B1 radio-frequency (RF) excited fields
14 main magnetsSignal phase
16 check space σ electrical conductivity
18 central shafts
20 objects
22 magnetic gradient coil systems
24 people's interface equipments
26 control units
28 memory cells
30 processor units
32 volume of interest
34 partitioning boundaries
36 radio shieldings
38 radio-frequency antenna equipment
40 radio frequency switch units
42 radiofrequency launchers
44 signal processing units
46 software modules
The step of 48 segmentations
The step of 50 extrapolation phase values
52 steps replaced
54 transform to the step in frequency domain
56 steps being multiplied
58 transform to the step in spatial domain
The step of 60 filtering
Detailed description of the invention
Fig. 1 shows the indicative icon of the part of the embodiment of magnetic resonance imaging system 10, described nuclear magnetic resonance system
System 10 is arranged to gather at least part of magnetic resonance image (MRI) of objects 20 (typically patient).Nuclear magnetic resonance system
System 10 includes the scanning element 12 with main magnet 14.Main magnet 14 has for providing objects 20 to be located at it
In the central bore checking space 16 around central shaft 18, and also be provided at least check in space 16 generate quiet
State magnetic field B0.Static magnetic field B0Definition is parallel to the axial direction checking space 16 of central axis 18 alignment.It should be understood that this
Invention also apply be applicable to provide the magnetic resonance imaging system of any other type of the inspection area in static magnetic field.
Additionally, magnetic resonance imaging system 10 includes that magnetic gradient coil system 22, magnetic gradient coil system 22 are arranged to
Generation is added to static magnetic field B0Gradient magnetic.Magnetic gradient coil system 22 is placed concentrically in the thorax of main magnet 14.
Magnetic resonance imaging system 10 includes that control unit 26, control unit 26 are configured to control magnetic resonance imaging system 10
Function.Control unit 26 includes that human interface device 24, human interface device 24 include having the monitoring list touching sensitivity screen
Unit.
It addition, magnetic resonance imaging system 10 includes that radio-frequency antenna equipment 38, radio-frequency antenna equipment 38 are designed to whole body line
Circle, described whole-body coil is provided for radio-frequency (RF) excited field B1Apply to objects 20 or atomic nucleus that it is interior be used for
Magnetic resonance excitation during the radio-frequency transmissions time period, with for nuclear magnetic resonance purpose excitation objects 20 or in it
Atomic nucleus.For this purpose it is proposed, controlled by control unit 26, radio-frequency power is fed to whole-body coil from radiofrequency launcher 42.Entirely
Body coil has central axis, and in operational state, is arranged concentrically in the thorax of main magnet 14 so that whole-body coil
Central shaft consistent with the central shaft 18 of scanning element 12.As known in the art, cylindrical metal radio shielding 36 is same
The heart is arranged between magnetic gradient coil system 22 and whole-body coil.
Whole-body coil be further provided with for during the radio frequency reception stage from by the radio-frequency field B launched1Excitation
The part of objects 20 or its interior atomic nucleus receive magnetic resonance signal.Mode of operation at magnetic resonance imaging system 10
In, radio-frequency transmissions stage and radio frequency reception stage occur in a continuous manner.
RF transmitter unit 42 is configured by control unit 26, start and is controlled, with during the radio-frequency transmissions stage via
Radio frequency switch unit 40 by magnetic resonance radio frequency and take three-dimensional balancing Turbo Field Echo (3D-BFFE) sequence radio-frequency pulse sequence
The radio-frequency power of the form (among other forms) of row is fed to whole-body coil and magnetic gradient coil system 22.Each pulse sequence
Row are configured to generate radio-frequency field B via radio-frequency antenna equipment 381, and generate magnetic gradient field via magnetic gradient coil system 22,
Wherein, pulse train is for static magnetic field B0Change be relative insensitivity.
During the radio frequency reception stage, control unit 26 the radio frequency switch unit 40 controlled is by the magnetic from whole-body coil
Resonance signal is directed to the signal processing unit 44 residing in control unit 26.Signal processing unit 44 is arranged to process
The magnetic resonance signal gathered, to obtain the magnetic resonance image (MRI) of the section of at least part of (i.e. the head) that represent objects 20
Magnetic resonance image data.The exemplary results obtained is scanned at Fig. 3 (a) and 3 from the 3D-bFFE of the head of objects 20
C () is illustrated.Fig. 3 (a) shows the magnitude image of slices across, and Fig. 3 (c) illustrates the whole head of objects 20
The signal phase image of slices across.
In the following, it is described that the embodiment of electrical property tomography method, described method is for according to representing interested
The magnetic resonance image data of at least part of magnetic resonance image (MRI) of object 20 rebuilds the spatial distribution of conductivityσ.It is presented in Fig. 2
The broad flow diagram of method.In the preparation carrying out described method, it will be appreciated that the unit related to and equipment are in operation
In state, and illustratively it is configured as in Fig. 1.
In order to the method performing the specific operation as magnetic resonance imaging system 10, control unit 26 includes software mould
Block 46 (Fig. 1).Method step to be carried out is converted into the program code of software module 46, and wherein, program code may be implemented in
In the memory cell 28 of control unit 26 and can be performed by the processor unit 30 of control unit 26.
Method starts from such as the slices across of the whole head of the objects 20 of diagram in Fig. 3 (a) and 3 (c)
Magnetic resonance image (MRI).
In the first step 48 of method, dividing method based on head model be applied to by Magnetic Resonance Image Segmentation be
Corresponding to the voxel outside the voxel of volume of interest 32 and volume of interest 32, wherein, corresponding to the body of volume of interest 32
Element and the voxel outside volume of interest 32 are separated by partitioning boundary 34.Fig. 3 (b) and (d) respectively illustrate and are limited to segmentation
The magnitude image of the slices across of the head of the objects 20 of the volume of interest 32 within border 34 and phase image.
Image segmentation algorithm is commercially available now, such as conductInternal software module,
And will not be described in detail the most in this article.As used in this specification, phrase " partitioning algorithm " should have
Contain body but should not necessarily be limited by based on threshold value, cluster, compress, rim detection and the dividing method of histogram method.In principle, may be used
To use any partitioning algorithm showing as those of ordinary skills being suitable for.
In another step 50 of method, for the phase place of all collections of the voxel corresponding to volume of interest 32, three
Dimension parabolic functionNine parameters be determined so that three dimensional parabolic line functionFrom the meaning of least squares approach
Measured phase place it is similar in justice(r refers to position vector):
Approximations based on formula (2), corresponding at least magnetic of the voxel of the volume of interest 32 close to partitioning boundary 34
The acquisition phase value of resonance image data is extrapolated, to obtain the appointment of the outside and neighbouring volume of interest 32 of volume of interest 32
The extrapolation phase value of volume.In step (52) subsequently, corresponding to the outside and neighbouring volume of interest 32 of volume of interest 32
Volume voxel MR data acquisition phase value by extrapolate phase value replace.
This is illustrated in Fig. 3 (e) and 3 (f).Fig. 3 (e) shows extrapolation in the longitudinal direction.Fig. 3 (f) shows
Extrapolation in the lateral direction.
Then, in next step 54, the numerical value core of numerical second derivative value is represented, corresponding to the body of volume of interest 32
The described acquisition phase value of element and the extrapolation phase of the voxel corresponding to the outside and neighbouring volume of interest 32 of volume of interest 32
Place value is converted in frequency domain.Representing that the numerical value core of numerical second derivative can be such as by set K={1 ,-2,1} are in spatial domain
Defined in.
In following step 56, respectively, described acquisition phase value is multiplied by the numerical second derivative of frequency domain transform,
And phase value of extrapolating is multiplied by the numerical second derivative of frequency domain transform.As those skilled in the art recognize, this multiplication
The CPU time of more much less is needed than the corresponding convolution of the phase place in spatial domain and differential core.
In the last step 58 of this embodiment of method, the result of the step 56 being multiplied is converted in spatial domain.
In Fig. 3 (h), show that the space of the conductivityσ of the part in the district covering original magnetic resonance image rebuild by this way is divided
Cloth.If it is required, as the additional option to perform after the step 58 of the result of the step 56 that conversion is multiplied, can perform
Step 60 to magnetic resonance image data filtering in the spatial domain.
In order to compare, show in Fig. 3 (g) by using art methods according to same magnetic resonance image number
According to the alternative reconstruction of the spatial distribution to conductivityσ, it illustrates by using the embodiment of the method according to the invention
Eliminate the drop-wise artifact (artifacts of drops) along the electrical conductivity at brain edge.
Although to those skilled in the art it should be evident that be used for the head of objects 20 by exemplary description
Portion, but described method is also applied for representing the magnetic of the other parts (such as liver, kidney or prostate) including objects 20
The magnetic resonance image data of resonance image.
Although having illustrated and described the present invention in accompanying drawing and description above in detail, but such diagram and retouching
It should be considered as illustrative or exemplary for stating, and nonrestrictive；The invention is not restricted to the disclosed embodiments.This area
Technical staff by research accompanying drawing, disclosure and claims, when the present invention that practice is claimed it will be appreciated that
And realize other modification to the disclosed embodiments.In detail in the claims, word " include " being not excluded for other elements or
Step, and word "a" or "an" is not excluded for multiple.Although describing specific in mutually different dependent claims
Measure, but this does not indicates that the combination that these measures be cannot be used to advantage.Any reference in claim is the most not
The restriction to scope should be interpreted.
Claims (9)
1. an electrical property tomography method, for according at least part of magnetic resonance image (MRI) representing objects (20)
Magnetic resonance image data rebuild the spatial distribution of electrical conductivity (σ), described spatial distribution covers the district of described magnetic resonance image (MRI)
At least partly, and said method comprising the steps of:
-it is that the voxel corresponding to volume of interest (32) and described volume of interest (32) are outside by described Magnetic Resonance Image Segmentation
The step (48) of voxel, wherein, partitioning boundary (34) separate the described voxel corresponding to described volume of interest (32)
The described voxel outside with described volume of interest (32)；
-the most described magnetic resonance of the voxel corresponding to described volume of interest (32) of described partitioning boundary (34) will be adjacent to
The acquisition phase value of view data is extrapolated, outside and neighbouring described interested to obtain for described volume of interest (32)
The step (50) of the extrapolation phase value of the voxel of the volume of volume (32)；
-replaced corresponding to the outside and neighbouring described volume of interest (32) of described volume of interest (32) by described extrapolation phase value
The step (52) of acquisition phase value of MR data of voxel of described volume；
-transforming to the step (54) in frequency domain, numerical value kernel representation numerical second derivative, described acquisition phase value corresponds to described sense
The described voxel of volume of interest (32), and described extrapolation phase value is corresponding to the outside and neighbouring institute of described volume of interest (32)
State the described voxel of volume of interest (32)；
-respectively the numerical second derivative through frequency domain transform is multiplied by the acquisition phase value of frequency domain transform and by described through frequency domain
The numerical second derivative of conversion is multiplied by the step (56) of the extrapolation phase value of frequency domain transform；And
-step (58) that the result of the step (56) being multiplied is transformed in spatial domain.
The most described extrapolation phase value is selected as constant.
3. method as claimed in claim 1 or 2, wherein, the step (50) of extrapolation includes that three dimensional parabolic line is extrapolated.
4. the method as described in any one in aforementioned claim, wherein, the step (48) of segmentation uses based on model point
Segmentation method performs.
5. the method as described in any one in aforementioned claim, is additionally included in the step (60) being filtered in spatial domain,
Wherein, described step is after transforming to the step (58) in described spatial domain by the described result of the described step (56) being multiplied
It is performed.
6. the method as described in any one in aforementioned claim, wherein, described magnetic resonance image data represent include described
The magnetic resonance image (MRI) of in head, liver, kidney and the prostate of objects (20).
7. the magnetic resonance imaging system being arranged to gather at least part of magnetic resonance image (MRI) of objects (20)
(10), including:
-check space (16), its be provided as by described objects (20) at least described in be partially located in described inspection
In space；
-scanning element (12), it has main magnet (14), and described main magnet is arranged in described inspection space (16) raw
Become static magnetic field B0；
-magnetic gradient coil system (22), it is arranged to generation and is added to described static magnetic field B0Gradient magnetic；
-at least one radio-frequency antenna equipment (38), it is arranged to radio-frequency (RF) excited field B1It is applied to described objects
(20) atomic nucleus in the atomic nucleus of described part or described part for magnetic resonance excitation,
-at least one radio-frequency antenna equipment (38), it is arranged to from by applying described radio-frequency (RF) excited field B1Excitation
Described atomic nucleus in the described atomic nucleus of the described part of described objects (20) or described part receives magnetic resonance letter
Number；
-control unit (26), its function being arranged to control described magnetic resonance imaging system (10)；And
-processor unit (30), it is any that it is configured in execution method as described in any one in claim 1-6
Step (48-60).
8. magnetic resonance imaging system (10) as claimed in claim 7, wherein, described control unit (26) is configured to start arteries and veins
Rushing sequence, wherein, each pulse train is configured to generate radio-frequency field via at least one radio-frequency antenna equipment (38) described,
And generate magnetic gradient field via described magnetic gradient coil system (22), and wherein, described pulse train is to described static state
Magnetic field B0Change insensitive.
9. a software module (46), for perform as described in any one in claim 1 to 6 according to represent interested right
The method rebuilding the spatial distribution of electrical conductivity (σ) as the magnetic resonance image data of at least part of magnetic resonance image (MRI) of (20), its
In, method step (48-60) to be implemented is converted into the program code of described software module (46), wherein, described program
Code can be implemented in the memory cell (28) of described magnetic resonance imaging system (10), and can be become by described magnetic resonance
As the processor unit (30) of system (10) performs.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP14164942.6 | 2014-04-16 | ||
| EP14164942 | 2014-04-16 | ||
| PCT/EP2015/057856 WO2015158625A1 (en) | 2014-04-16 | 2015-04-10 | Ept method of electric conductivity reconstruction with enhanced stability and speed |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106232002A true CN106232002A (en) | 2016-12-14 |
| CN106232002B CN106232002B (en) | 2019-09-03 |
Family
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201580019778.XA Expired - Fee Related CN106232002B (en) | 2014-04-16 | 2015-04-10 | The EPT method that the conductivity of stability and speed with enhancing is rebuild |
Country Status (4)
| Country | Link |
|---|---|
| US (1) | US10185011B2 (en) |
| EP (1) | EP3132277B1 (en) |
| CN (1) | CN106232002B (en) |
| WO (1) | WO2015158625A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113301841A (en) * | 2019-01-14 | 2021-08-24 | 皇家飞利浦有限公司 | Zone specific downscaling of high frequency to low frequency conductivity for EEG |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11047935B2 (en) | 2015-05-14 | 2021-06-29 | Ohio State Innovation Foundation | Systems and methods for estimating complex B1+ fields of transmit coils of a magnetic resonance imaging (MRI) system |
| US10890631B2 (en) | 2017-01-19 | 2021-01-12 | Ohio State Innovation Foundation | Estimating absolute phase of radio frequency fields of transmit and receive coils in a magnetic resonance |
| CN107563988A (en) * | 2017-07-31 | 2018-01-09 | 上海东软医疗科技有限公司 | The uniformity correcting method and device of a kind of MRI |
| EP3543724A1 (en) | 2018-03-20 | 2019-09-25 | Koninklijke Philips N.V. | (3-n)-dimensional determination of electric conductivity |
| EP3581090A1 (en) * | 2018-06-11 | 2019-12-18 | Koninklijke Philips N.V. | Electrical properties tomography mapping of conductivity changes |
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| CN102713657B (en) * | 2010-01-18 | 2016-03-02 | 皇家飞利浦电子股份有限公司 | Electrical property tomographic imaging method and system |
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| US9645214B2 (en) * | 2013-11-27 | 2017-05-09 | General Electric Company | Systems and methods for determining electrical properties using magnetic resonance imaging |
| KR101623310B1 (en) * | 2015-06-18 | 2016-05-20 | 경희대학교 산학협력단 | Apparatus and method for electrical properties tomography using magnetic resonance |
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2015
- 2015-04-10 WO PCT/EP2015/057856 patent/WO2015158625A1/en active Application Filing
- 2015-04-10 EP EP15715271.1A patent/EP3132277B1/en not_active Not-in-force
- 2015-04-10 US US15/302,565 patent/US10185011B2/en active Active
- 2015-04-10 CN CN201580019778.XA patent/CN106232002B/en not_active Expired - Fee Related
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| CN1714746A (en) * | 2005-07-14 | 2006-01-04 | 中国人民解放军第四军医大学 | Non-contact Magnetic Induction Cerebral Edema Monitoring Method |
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| CN113301841A (en) * | 2019-01-14 | 2021-08-24 | 皇家飞利浦有限公司 | Zone specific downscaling of high frequency to low frequency conductivity for EEG |
Also Published As
| Publication number | Publication date |
|---|---|
| US10185011B2 (en) | 2019-01-22 |
| US20170030988A1 (en) | 2017-02-02 |
| EP3132277B1 (en) | 2020-10-14 |
| EP3132277A1 (en) | 2017-02-22 |
| WO2015158625A1 (en) | 2015-10-22 |
| CN106232002B (en) | 2019-09-03 |
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